An articulated tug-barge carrying stone and nearly 100,000 gallons of diesel ran hard aground in a narrow section of the Straits of Mackinac, but the ATB was able to float free less than a day later without being breached.
The 7,200-hp tugboat Defiance and barge Ashtabula were heading west when the barge left the channel and became stuck in Round Island Passage on the far west side of Lake Huron. Crew reported the incident at about 1500 on Sept. 21.
There were no injuries or pollution, and the vessels did not sustain any serious damage, according to U.S. Coast Guard Lt. Sean Murphy of Sector Sault Ste. Marie. He said the cause remains under investigation.
“This passage is where ships regularly come through every single day. If a ship … stays within the buoys, they don’t run aground,” Murphy said. “It is clearly charted as shallow water where it ran aground.”
Grand River Navigation Co. of Traverse City, Mich., a subsidiary of Rand Logistics, owns and operates the ATB unit. The company’s spokeswoman did not respond to a request for comment about the incident.
Defiance and the 610-foot Ashtabula left Cedarville on Michigan’s Upper Peninsula and were en route to Gary, Ind., when the grounding occurred. At the time, the vessels had 2,917 tons of stone and 97,918 gallons of diesel on board.
The ATB was navigating Round Island Passage between Mackinac and Round Island when Ashtabula grounded between buoys 3 and 5, leaving the barge’s port bow stuck on the clay bottom. However, the vessels came free on their own at about 0430 on Sept. 22.
“(The crew) reported to us that in the middle of the night, the current pushed them off and they were able to get underway,” Murphy said.
Inspectors from the Coast Guard and the vessels’ class society boarded the ATB later that morning at a nearby anchorage. After finding no flooding or pollution, the inspectors cleared the vessels to continue their voyage to Indiana.
Coast Guard air crews flew over the Straits of Mackinac searching for signs of pollution in the waterway but found none.
The U.S. Army Corps of Engineers surveyed the federal channel following the incident. The Corps found no evidence of disturbances to the shoal or impacts to the channel itself, Murphy said.
Marinette Marine of Wisconsin built Defiance in 1982. With the self-unloading Ashtabula, the unit makes up one-third of the Grand River Navigation ATB fleet. In late June, the company announced that Defiance had earned a Coast Guard certificate of inspection under Subchapter M, the first Great Lakes tugboat to do so.